After seven years in the preparation stage, the U.S. Environmental Protection Agency published, on August 29, 1979, its hazardous substances regulations, setting forth which chemicals are considered hazardous to the environment, which are removable if spilled into a water body, and rate of penalties for spilling. This paper reviews the basis of the regulations (the Federal Water Pollution Control Act), the various drafts issued and withdrawn by EPA, the philosophy behind each and, lastly, details of the final regulations. (Copyright (c) 1981 Elsevier Scientific Publishing Company.)